Study on the influence of flame inherent instabilities on crack propagation of expanding premixed flame

Jiang, Yan-Huan; Li, Guo-Xiu; Li, Hong‐Meng; Li, Lei; Tian, Lili

doi:10.1016/j.fuel.2018.06.088

Cited by 27 publications

(3 citation statements)

References 29 publications

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“…Khan et al [48] obtained the same tendency in the variation of calculated laminar flame thickness versus the equivalence ratio, for different hydrogen/methane mixtures. Hydrodynamic instability and thermal-diffusive instability are the main contributions to the cellular structure formation [36,59,60]. The destabilization in hydrogen combustion due to hydrodynamic instability is reflected by the decrement in the flame front thickness (δ) [61], as can be seen in Figure 12, where the effect of the hydrogen content in the fuel/air mixture on the flame front thickness is presented [17].…”

Section: Flame Morphological Studymentioning

confidence: 97%

Experimental, Kinetic Modeling and Morphologic Study of the Premixed Combustion of Hydrogen/Methane Mixtures

Reyes¹,

Sastre²,

Giménez³

et al. 2022

Energies

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In this work, an experimental study and kinetic characterization of the combustion process and a morphologic study of hydrogen/methane–air mixtures are presented. The experimental study was performed in an optical access cylindrical constant-volume combustion bomb. This bomb is equipped to register the instantaneous pressure during combustion and records the combustion images using the high-speed Schlieren optical technique. This provides straightforward information to compute the flame propagation speed and direct evidence of the apparition of cellularity on the flame front. Through the images of the combustion process, it is possible to conduct a morphological study of the process using a flame monitoring model. Simultaneously, by means of a two-zone thermodynamical model, with the temporal evolution of pressure as the main intake, significant parameters are determined during the combustion process of different fuels under premixed conditions: burning velocity, rate of combustion, burned and unburned temperature, burned mass fraction, and rate of heat release, among others. Experimental results are compared with kinetic modeling results obtained with the Cantera package using the Gri-Mech 3.0 kinetic mechanism. Results show that a greater percentage of hydrogen in the fuel mixture increases the burning velocity and the cellularity of the flame front surface. At the same time, leaner mixtures and higher equivalence ratios enhance the apparition of the cellularity onset in the flames. Burning velocity increases with the increase in the initial temperature and the fuel/air mixture equivalence ratio. All the results obtained were validated with other data from the literature.

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Section: Flame Morphological Studymentioning

confidence: 97%

Experimental, Kinetic Modeling and Morphologic Study of the Premixed Combustion of Hydrogen/Methane Mixtures

Reyes¹,

Sastre²,

Giménez³

et al. 2022

Energies

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“…The flame destabilization process is an essential transition from laminar to turbulent combustion, which is a key ingredient for inducing a large-scale explosion. As mentioned above, the emergence of cellular structures in the spherical expanding flame surface causes flame propagation into the flame acceleration stage, mainly owing to thermal diffusion and hydrodynamic instabilities. , Based on the flame stability analysis method, , the logarithmic growth rate of disturbance ( A ) can be used to identify whether the flame is in a stable state, which is defined as follows: A false( n , P e false) = ω − Ω P e where n refers to the wavenumber and Pe denotes the Peclet number, which presents the dimensionless flame radius normalized by flame thickness δ = ( T b − T u )/((d T /d x ) max ). ω and −Ω/ Pe indicate the hydrodynamic and thermal diffusion effects, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…As mentioned above, the emergence of cellular structures in the spherical expanding flame surface causes flame propagation into the flame acceleration stage, mainly owing to thermal diffusion and hydrodynamic instabilities. 60,61 Based on the flame stability analysis method, 62,63 the logarithmic growth rate of disturbance (A) can be used to identify whether the flame is in a stable state, which is defined as follows:…”

Section: Flame Propagation Analysismentioning

confidence: 99%

Study on Explosion Characteristics of Ammonia/Dimethyl Ether/Air with Different Mixed Compositions

et al. 2023

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The blend of ammonia (NH3) and dimethyl ether (DME) is a promising renewable and clean fuel. This work studies the basic explosion characteristics of NH3/DME/air with varying equivalence ratios (from 0.6 to 1.8) and DME fractions (from 0.2 to 1). Three essential parameters, i.e., explosion pressure (P max), explosion time (t c), and maximum pressure rise rate ((dP/dt)max), were experimentally obtained, and the heat loss during the explosion was quantitatively analyzed. Besides, the heat release characteristics and critical flame radius of destabilization in the explosion process were analyzed using the detailed NH3/DME reaction mechanism. The results showed that adding DME to the mixture can significantly increase the P max, increase the (dP/dt)max, and shorten the t c. The heat loss during the NH3/DME/air explosion mainly presents a negative correlation with the explosion intensity, as reflected by (dP/dt)max and t c. In addition, at stoichiometric ratios, the elementary reaction R12: H + OH + M = H2O + M contributes most to the total heat release of the NH3/DME/air explosion, while the NH3- or DME-related reactions subdominate the total heat production. Adding DME reduces the critical flame radius, causing the flame to enter an unstable state earlier, which is mainly dominated by the hydrodynamic effect.

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Study on difference and adaptability of calculation method of spherical flame radius

Han

Xiao

Tian

et al. 2020

Fuel

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Study on the influence of flame inherent instabilities on crack propagation of expanding premixed flame

Cited by 27 publications

References 29 publications

Experimental, Kinetic Modeling and Morphologic Study of the Premixed Combustion of Hydrogen/Methane Mixtures

Experimental, Kinetic Modeling and Morphologic Study of the Premixed Combustion of Hydrogen/Methane Mixtures

Study on Explosion Characteristics of Ammonia/Dimethyl Ether/Air with Different Mixed Compositions

Study on difference and adaptability of calculation method of spherical flame radius

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